Electronic device case

ABSTRACT

A case for an electronic device is provided. The case includes a battery, an interface to receive electrical current from an external power source, and a computer processor. The computer processor is configured to execute computer-readable instructions to receive a communication from the electronic device, limit the received electrical current to a current limit, and allocate the electrical current among the battery and the electronic device based on the received communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application61/749,244, filed Jan. 4, 2013, and U.S. Provisional Application61/783,212, filed Mar. 14, 2013, both of which are hereby incorporatedby reference in their entirety.

FIELD

The present application relates to cases for electronic devices. Morespecifically, the present application relates to a protective case thatincludes power management features.

BACKGROUND

Many types of electronic devices are used for communication andentertainment purposes. Electronic devices include devices such ascellular phones, smartphones, mobile communication devices, tablets,computers, cameras, video players, electronic media readers, audioplayers, handheld scanners, two-way radios, global positioning satellite(GPS) devices, and other types of electronic computing or communicationdevices, including combinations thereof. These devices often containsensitive or fragile components, such as electronic components or glassscreens, which can be easily damaged if the device is dropped or exposedto substantial forces. To protect the device from damage, it can beinstalled in a protective enclosure.

Electronic devices are commonly powered by one or more internalbatteries. These batteries are often rechargeable. Typically, deviceswith more computational power and/or larger displays consume theavailable battery power more quickly. If an electronic device's batteryis exhausted, the device may become unusable until the battery can berecharged or until the device can be connected to another power source.Battery capacity often becomes an issue due to factors such as: powerrequirements of the electronic device, extended usage of the electronicdevice, physical space constraints of the battery, power requirements ofperipherals attached to the electronic device, temperature extremes,unavailability of a power source for charging, decreased batterycapacity due to aging of the battery, decreased battery life due to thenumber of charge/discharge cycles a battery has endured, or combinationsthereof. These factors can reduce the usefulness of electronic devicesbecause use time of the device between recharges becomes shorter and theuser must typically recharge the device before use can continue.

In some situations, a user may carry a spare battery for the electronicdevice that has been previously charged but is not electricallyconnected to the electronic device. The spare battery can be used as areplacement for a discharged battery. While carrying the spare batteryenables the user to use the device again without having to find acharging source, this approach has drawbacks. First, the user mustremember to carry the spare battery(s), in addition to the electronicdevice, because the spare battery will not typically be physicallyattached to the electronic device when not in use. Second, replacing anexhausted battery, or swapping an exhausted battery into the electronicdevice for charging purposes, typically requires that the device be shutdown, or otherwise turned off, and restarted or rebooted. This processis often inconvenient and typically results in temporary loss ofcommunication and/or data. Finally, when a charging source is available,the various batteries must be swapped into and out of the electronicdevice in order to charge them, unless a separate host charging deviceis available for the extra battery.

In some situations, some of the problems discussed above are resolvedthrough use of a supplemental battery pack that attaches to theelectronic device. The battery pack is mechanically and electricallyattached to the electronic device in a manner such that the electronicdevice can make use of both its internal battery and a supplementalbattery in the battery pack without having to shut down the electronicdevice, or otherwise temporarily remove power from the electronicdevice. However, existing solutions have drawbacks.

From an electrical standpoint, existing solutions take one of twoapproaches regarding how the two batteries (a battery in the externalcase for the electronic device and a battery inside the electronicdevice itself) are charged. In one approach, the two batteries are usedand/or charged alternately. At any point in time the electronic deviceis only utilizing one of the batteries or is only charging one of thebatteries. When the batteries are not being charged and one of thebatteries becomes discharged, or becomes sufficiently low in power, theelectronic device and/or the case switches usage from one of thebatteries to the other. This approach has the limitation that one of thebatteries may be exhausted before use of the other begins. If theinternal battery is exhausted first and the electronic device isoperating off of the supplemental battery, the user no longer has theflexibility of removing the supplemental battery/case from the deviceand using the electronic device without it.

In an alternate approach, both batteries are used and/or chargedsimultaneously as if they are a single battery. This approach presentsseveral problems. First, the user and/or the electronic device cannotselectively control which of the batteries is charged first. Second,charging batteries in parallel may not be a preferred method if thebatteries have different characteristics. Third, charging both batteriessimultaneously may draw too much current from the power source and/orotherwise exceed the specifications of the power source. For example, aUniversal Serial Bus (USB) interface may only be specified to provide500 mA (milliamperes) of current and charging both batteriessimultaneously may exceed that limit. Drawing too much current from apower source may damage the power source, may damage the device thathosts the power source (i.e., the computer in which a USB port islocated), may cause the power source to overheat, or may cause the powersource or host device to enter a failsafe mode which discontinues poweruntil the power source or host device is reset and/or rebooted.

SUMMARY

In one embodiment, a case for an electronic device includes a battery,an interface to receive electrical current from an external powersource, and a computer processor. The computer processor is configuredto execute computer-readable instructions to receive a communicationfrom the electronic device, limit the received electrical current to acurrent limit, and allocate the electrical current among the battery andthe electronic device based on the received communication.

While multiple embodiments are disclosed, still other embodiments willbecome apparent to those skilled in the art from the following detaileddescription, which shows and describes illustrative embodiments of theinvention. As will be realized, the invention is capable ofmodifications in various aspects, all without departing from the scopeof the present invention. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and notrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described and explainedthrough the use of the accompanying drawings in which:

FIG. 1 is a front perspective view of a protective enclosure for anelectronic device;

FIG. 2 is an exploded front perspective view of a protective enclosurefor an electronic device;

FIG. 3 is an exploded rear perspective view of a protective enclosurefor an electronic device;

FIG. 4 is a rear perspective view of a back shell of a protectiveenclosure for an electronic device;

FIG. 5 is a front perspective view of a back shell of a protectiveenclosure for an electronic device;

FIG. 6 is an exploded front perspective view of a back shell of aprotective enclosure for an electronic device;

FIG. 7 is an exploded rear perspective view of a back shell of aprotective enclosure for an electronic device;

FIG. 8 is a front perspective view of a back shell of a protectiveenclosure for an electronic device.

FIG. 9 illustrates a case for an electronic device with components formanaging power in one embodiment of the techniques disclosed herein;

FIG. 10 illustrates a case interfaced to a power source and a device inone embodiment of the techniques disclosed herein;

FIG. 11 illustrates a method of distributing current between a case andan electronic device in one embodiment of the techniques disclosedherein;

FIG. 12 illustrates an alternate method of distributing current betweena case and an electronic device in another embodiment of the techniquesdisclosed herein;

FIG. 13 illustrates a computer system for performing the techniquesdisclosed herein;

FIG. 14 illustrates an example of a power remaining display;

FIG. 15 illustrates an example of a daily power consumption display;

FIG. 16 illustrates alternate examples of power remaining displays;

FIG. 17 illustrates an example of a power remaining versus time display;

FIG. 18 illustrates alternate examples of power remaining displays;

FIG. 19 illustrates an example of displaying battery charge information;

FIG. 20 illustrates an example of displaying battery charge informationwhen one battery is not fully charged;

FIG. 21 illustrates an example of displaying battery charge informationwhen two batteries are not fully charged;

FIG. 22 illustrates an example of displaying battery charge informationwhen power is being received from an external power source;

FIG. 23 illustrates an example of displaying time remaining informationbased on battery charge information.

DETAILED DESCRIPTION

In the following detailed description, various specific details are setforth in order to provide an understanding of and describe theapparatuses and techniques introduced here. However, the techniques maybe practiced without the specific details set forth in these examples.Various alternatives, modifications, and/or equivalents will be apparentto those skilled in the art without varying from the spirit of theintroduced apparatuses and techniques. For example, while theembodiments described herein refer to particular features, the scope ofthis solution also includes embodiments having different combinations offeatures and embodiments that do not include all of the describedfeatures. Accordingly, the scope of the techniques and solutionsintroduced herein are intended to embrace all such alternatives,modifications, and variations as fall within the scope of the claims,together with all equivalents thereof. Therefore, the description shouldnot be taken as limiting the scope of the invention, which is defined bythe claims.

FIG. 1 is a front perspective view of a protective enclosure for anelectronic device. A protective enclosure 100 for an electronic devicecan include a hard shell that at least partially surrounds and protectsthe electronic device. The hard shell can include a front shell 210 anda back shell 215. The front shell 210 can attach to the back shell 215in any suitable way to form the hard shell. The front shell 210 cancover at least a portion of a front surface of the electronic device205, and the back shell 215 can cover at least a portion of a backsurface of the electronic device. In one example, the back shell 215 canalso cover a portion of the front surface of the electronic device, asshown in FIG. 2. The hard shell can be made from any suitable material,such as polycarbonate or any other suitable type of polymer, nylon,fiberglass-filled nylon, or carbon fiber.

The hard shell can include a plurality of retention features that allowthe front shell 210 to attach to the back shell 215. For example, thefront shell 210 can include a plurality of tabs (e.g. 235, 240)extending from a mating edge 245 of the front shell 210. The pluralityof tabs (235, 240) can be configured to engage a mating edge 250 of theback shell 215, as shown in FIGS. 2 and 3. At least one of the tabsextending from the mating edge 245 of the front shell 210 can beconfigured to slide behind the mating edge 250 of the back shell 215. Atleast one of the tabs extending form the mating edge 245 of the frontshell 210 can be configured to slide in front of the mating edge 250 ofthe back shell 215. The back shell 215 can include a recess 255 toreceive each tab (e.g. 235, 240). In one example, as shown in FIGS. 2and 3, the front shell 210 can include four tabs (235, 240) extendingfrom its mating edge 245. The two outer tabs 235 can slide behind themating edge 250 of the back shell 215, and the two inner tabs 245 canslide in front of the mating edge 250 of the back shell 215. In thisway, the mating edge 250 of the back shell 215 can be sandwiched betweenthe inner and outer tabs (235, 240) that extend from the front shell210, which can resist motion of the front shell relative to the backshell.

Although one embodiment is shown and described, this is not limiting.The number, placement, and dimensions of the tabs (235, 240) can vary.For example, tabs can extend from the back shell 215 instead of from thefront shell 210. Alternately, the tabs (235, 240) can extend from bothshells. The tabs (235, 240) can be wider or narrower than the tabs shownin FIGS. 2 and 3. In one example, the tabs can have a width of about0.25 to 2.0 in. In another example, the tabs (235, 240) can extend thelength of the mating edge 245 of the front shell 210. Also, more orfewer than four tabs can be used. Alternately, retention features otherthan tabs can be used. Alternatively, the protective case may beconfigured to include a back shell without a front shell, or a frontshell without a back shell. In either instance, tabs may extend from ashell to engage with the electronic device itself to mount the shell tothe electronic device. The tabs can assist in holding the electronicdevice 205 securely against the front or back shell. Although aprotective case with only a front or back shell may not provide as muchprotection for the electronic device as a case with both a front andback shell, some users may prefer this configuration to reduce the size,weight, or complexity of the protective case.

The hard shell can include a plurality of retention features that allowthe front shell 210 to attach to the back shell 215. In one example, thehard shell can include a plurality of tabs extending from one of thehard shell components (e.g. front or back shell), and the plurality oftabs can snap into a plurality of corresponding slots on the opposinghard shell component. For example, as shown in FIGS. 2 and 3, the backshell 215 can include a plurality of tabs 260 extending from locationsnear its perimeter, and the plurality of tabs can be configured to snapinto a plurality of slots 265 located near the perimeter of the frontshell 210. In one example, the plurality of tabs 260 can extendoutwardly from the left side, right side, and top end of the back shell215 and snap into the plurality of slots 265 in the left side, rightside, and top end of the front shell 210. In another example, the tabs260 can extend from the front shell 210 and snap into correspondingslots 265 on the back shell 215. Similarly, any other suitable retentionfeatures can be used as a substitute for the plurality of tabs and slotsto attach the front shell 210 to the back shell 215.

The hard shell can include various openings to allow for operability ofthe electronic device 205 by a user when installed in the protectiveenclosure 100. For example, for a protective enclosure 100 for an APPLEIPHONE, the hard shell can include an opening 270 to accommodate a firstspeaker 206 and a front-facing camera 207 located on a front surface ofthe electronic device 205. The hard shell can include an opening for aswitch 309 located on a left side surface of the electronic device 205.The hard shell can include openings for volume control buttons 311located on the left side of the electronic device 205. The hard shellcan include openings for a headphone jack 212 and power button 213located on a top side surface of the electronic device 205. The hardshell can include openings for a microphone 214 and a second speaker 216on a bottom side surface of the electronic device 205. In one example,as shown in FIGS. 3 and 7, the back shell 215 can include a microphoneopening 365 and a second speaker opening 360. The microphone opening 365can be designed to avoid introducing echoes or reverberations into thesound waves that are received by the microphone 214 of the electronicdevice 205. The hard shell can include an opening 275 for a camera 217and a flash 218 located on a back surface of the electronic device 205.

In one example, the back shell 215 can wrap around a bottom side of theelectronic device 205. The back shell 215 can include a cavity 805, asshown in FIG. 8, which is configured to receive a bottom portion of theelectronic device 205. The electronic device 205, which can be asmartphone, can include a female connector 305 proximate a bottom sidesurface of the device. The cavity 805 of the hard shell case can includea male connector 810 configured to mate with the female connector 305 ofthe electronic device 205. The male connector 810 can be configured totransfer power and data to and from the electronic device 205. The typeof male connector in the cavity can be determined by the type ofelectronic device 205 for which the protective enclosure 100 is designedto house. In one example where the protective enclosure 100 isconfigured to house an APPLE IPHONE, the male connector 805 can beAPPLE'S proprietary 30-pin connector. In another example, a protectiveenclosure similar to protective enclosure 100 is configured to house aSAMSUNG smartphone.

The hard shell can include a membrane 310 to allow for operability of atouch screen 208 on the electronic device 205 when housed in theprotective enclosure 100. For example, the front shell 210 can include adisplay opening that is covered by the membrane 310, which can beflexible or rigid. In one example, the membrane 310 can be made from athin layer of polycarbonate (e.g. LEXAN), polyvinyl chloride (PVC),polyurethane, tempered glass, alkali-aluminosilicate sheet glass (e.g.GORILLA GLASS), or silicone that can be molded or formed, such as bythermoforming, casting, stretching, heating, or injection molding, orotherwise shaped to fit over the front surface of the electronic device205 or other surfaces of the electronic device. The membrane 310 canhave a thickness ranging from about 0.004 to 0.020 inches. The membrane310 can be made from a single material or multiple materials that arewelded, glued, or formed together into a single membrane. In oneexample, the membrane can include a privacy filter, such as amicrolouver layer or other light control layer, to enhance visualsecurity of information displayed on the screen of the electronicdevice. The privacy filter can make the screen of the electronic appeardark to any person not viewing the screen head on. For a portion of themembrane 310 that is disposed over the touch screen 208 of theelectronic device 205, it can be desirable to use a clear, thin layer ofglass or plastic to provide a clear, transparent material over thescreen to protect the screen from scratches while also permittingoperability of the touch screen. If the electronic device 205 includes akeyboard, a portion of the membrane 310 that covers the keyboard can bemade of a thin layer of polycarbonate (e.g. LEXAN), PVC, polyurethane,or silicone that is flexible so that the keyboard or other buttons canbe pressed through the membrane, which can provide a similar feel asusing the keyboard without the membrane 310.

The protective enclosure 100 can include a stretchable cushion layer 220over an outer surface of the hard shell. The stretchable cushion layer220 can fit snugly over the assembled hard shell. The stretchablecushion layer 220 can provide cushioning to the electronic device 205 ifit is dropped. The stretchable cushion layer 220 can be made of anysuitable material, such as silicone rubber or thermoplastic elastomer(TPE), including silicone-based thermoplastic. The stretchable cushionlayer 220 can be capable of stretching sufficiently to allow the hardshell to slide into a front opening 221 of the stretchable cushionlayer.

The stretchable cushion layer 220 can attach to the hard shell by anysuitable method of attachment, such as through one or more retentionfeatures. Positively attaching the stretchable cushion layer 220 to thehard shell can resist movement of the stretchable cushion layer 220relative to the hard shell and can improve appearance and functionalityof the protective case 100. In one example, as shown in FIG. 2, thefront shell can include a groove 280. The groove 280 in the front shell210 can extend around a perimeter of the display opening that, in oneexample, can be occupied by the membrane 310. The groove 280 can becontinuous around the perimeter of the display opening in the frontshell 210. Alternately, there can be a plurality of discontinuousgrooves 280 located around the perimeter of the display opening in thefront shell 210. The stretchable cushion layer 220 can include a tab(not shown) on an inner surface of the stretchable cushion layerextending around a perimeter of its front opening 221. In one example,the tab can be located on the inner surface of the stretchable cushionlayer 220 and within about 0-0.2, 0-0.1, or 0-0.05 inch of the perimeterof the front opening 221.

The tab of the stretchable cushion layer 220 can be configured to matewith the groove 280 or grooves in the front shell 210. The tab can becontinuous on the inner surface of the stretchable cushion layer 220extending around the perimeter of the front opening 221. Alternately,there can be a plurality of discontinuous tabs located on the innersurface of the stretchable cushion layer 220 extending around theperimeter of the front opening 221. The tab can extend from an innersurface of the stretchable cushion layer 220 toward an inner volume ofthe stretchable cushion layer in a direction parallel to a side surfaceof the stretchable cushion layer. Upon assembling the stretchablecushion layer 220 over the hard case, the user can depress the tab intothe groove by pressing a finger against a front surface of thestretchable cushion layer proximate each tab and around the perimeter ofthe front opening 221 Each tab and corresponding groove can have anysuitable length or width. In one example, each tab can have a width ofabout 0.01-0.1, 0.01-0.05, or 0.01-0.03. The tab can be slightly widerthan the groove to provide a friction fit, which can enhance retentionof the tab within the groove. In addition, the tab can be made of a softmaterial with a relatively high coefficient of friction, such assilicone rubber or any thermoplastic elastomer, which can be slightlycompressed as it is pressed into the groove. The compressed tab canexert an outward force against side surfaces of the groove, and due toits relatively high coefficient of friction, the soft material canresist movement of the tab relative to the groove. The end of each tabcan be tapered to enhance ease of insertion of the tab into the grooveand to enhance manufacturability of the stretchable cushion layer 220 byimproving its mold release characteristics.

The hard shell can include retention features to resist relativemovement of the stretchable cushion layer 220 with respect to the hardshell. As shown in FIGS. 2 and 3, the front shell 210 can include sidetabs 285 that extend outwardly from the hard shell. Each side tab 285can extend through a side opening 290 in the stretchable cushion layer220. The side tabs 285 can anchor the stretchable cushion layer 220 andresist relative movement of the stretchable cushion layer 220 withrespect to the hard shell. Each side tab 285 can have a length and widththat is suitable to provide sufficient contact surface areas between theside opening 290 in the stretchable cushion layer 220 and the side tab285 of the front shell 210 to resist relative movement of thestretchable cushion layer in either the lengthwise or widthwisedirection. In one example, the side tab 285 can have a length and widthof about 0.25 to 0.5, 0.25 to 1.0, or 0.25 to 2.0 in.

The stretchable cushion layer 220 can include buttons that can bedepressed by a user to activate corresponding buttons or switches on theelectronic device 205. Each button on the stretchable cushion layer 220can include a protrusion on an inner surface of the stretchable cushionlayer to improve the feel and effectiveness of the button. For example,for a volume control button 315 on the stretchable cushion layer 220,the inner surface of the stretchable cushion layer opposite the buttoncan include a protrusion 222 extending inward from the inner surface ofthe stretchable cushion layer and through an opening in the hard shell.The protrusion 222 can be configured to depress a corresponding volumecontrol button 311 on the electronic device 205. The protrusion 222 canbe shaped to provide a feel that mimics the feel associated withactuating the button of the electronic device 205 when the device is notinstalled in the protective enclosure 100.

The stretchable cushion layer 220 can include one or more flaps 320 thatcan be opened and closed. The flaps 320 can provide access to ports,buttons, or features of the electronic device 205. For example, as shownin FIG. 2, the stretchable cushion layer 220 can include a flap 320 thatprovides access to a headphone jack 212 on the electronic device 205. Asshown in FIG. 3, the stretchable cushion layer 220 can include a flap320 that provides access to a female connector 325 attached to theprotective enclosure 100. The female connector 325 can be any suitableconnector that allows for transmission of power and data to and from theelectronic device 205. In one example, as shown in FIG. 3, the femaleconnector 325 can be a mini USB connector. The mini USB connector 325can connect to a USB cable 230 that can allow the protective enclosure100 to be connected to a computer, wall charger, or other device havinga female USB port. Other types of connectors and cables are possible.

In one example, as shown in FIG. 3, an outer surface of the stretchablecushion layer 220 can include a surface texture made from a plurality ofsmall cavities in an outer surface of the stretchable cushion layer. Thesurface texture can improve a user's grip on the protective enclosure100 and thereby reduce the likelihood of dropping the device 205. Thesurface texture can also increase the surface area of the stretchablecushion layer and thereby improve heat transfer away from the protectiveenclosure 100 to reduce the operating temperature of the electronicdevice 205 within the protective enclosure, which may improve batteryperformance and life. Although a surface texture with cavities is shownin FIG. 3, this is not limiting. The surface texture can include anysuitable surface geometry that increases the surface area of thestretchable cushion layer 220 when compared to a smooth surface. Forexample, the surface texture can include small raised posts, fins, orother protrusions extending from the stretchable cushion layer 220.

The back shell 215 can include an inner back shell 610 and an outer backshell 615 as shown in FIG. 6. A battery 625 can be located between theinner back shell 610 and the outer back shell 615. The battery 625 canbe electrically connected to a circuit board 630 that interfaces withthe electronic device 205 though the male connector 810. In one example,the circuit board 630 can include a main circuit board 631 and aninterface circuit board 632, as shown in FIG. 6. The main circuit board631 can be electrically connected to the interface circuit board 632,and the male connector 810 can be mounted on the interface circuitboard.

The inner back shell 610 and outer back shell 615 can snap together tohouse the battery. Any suitable method of fastening the inner and outerback shells (610, 615) can be used including snaps, fasteners,adhesives, etc. An inner surface 635 of the inner back shell 610 caninclude a soft layer 605 that is configured to make contact with theback surface of the electronic device 205. The soft layer 605 can bemade of any suitable material, such as foam, felt, or rubber, and canprotect the electronic device 205 from scratches. The soft layer 605 canoccupy a clearance volume between the electronic device 205 and theinner surface 635 of the inner back shell and thereby prevent theelectronic device 205 from rattling inside the protective enclosure 100.

The battery 625 can be any suitable type of primary or rechargeablebattery, such as an alkaline, carbon-zinc, nickel-metal hydride,lithium, lithium ion, or lithium polymer battery. The protectiveenclosure 100 can include a single battery or a plurality of batteries.The battery 625 can be permanently or semi-permanently sealed in theback shell 215 or it can be easily removable. In one example, thebattery 625 can be removable and can be accessed without disassemblingthe protective enclosure 100. For example, the battery 625 can beinserted into the protective enclosure 100 through a battery slot (notshown). This can allow the user to easily replace a depleted batterywith a fresh or newly recharged battery. In this example, thestretchable cushion layer 220 can include a flap (not shown) to protectand conceal the battery slot. The flap can prevent dirt or debris fromentering the battery slot.

The battery 625 can be a single battery. Alternately, the battery 625can be a plurality of batteries. Providing a protective enclosure 100with a plurality of batteries can allow a first user to share power witha second user by swapping a charged battery for a depleted battery. Forexample, if a second user has depleted the batteries 625 in herprotective enclosure, the first user can provide the second user with acharged battery from her protective enclosure 100. The battery 625 canhave any suitable shape. For example, the battery can be a cuboid asshown in FIG. 6. Alternately, the battery can be a cylinder, hexagonalprism, triangular prism, or any other suitable shape. A protectiveenclosure having multiple batteries may also include multiple batteryslots to accommodate the multiple batteries and to allow individualbatteries to be removed or replaced.

The protective enclosure 100 may include a plurality of light emittingdiodes (LEDs) 640. The LEDs can be electrically connected to the circuitboard 630 of the protective enclosure 100. In one example, the LEDs 640can be mounted on the circuit board 630, and light pipes can be used totransfer light from each LED to a location some distance away from theLEDs. The hard shell of the protective enclosure 100 can include anopening through which light from the LEDs can be transmitted. Likewise,the stretchable cushion layer can include one or more openings throughwhich light from the LEDs is transmitted. In one example, thestretchable cushion layer 220 can include an LED opening 105 for eachLED, as shown in FIG. 1.

The LEDs 640 can indicate the charge remaining in the protectiveenclosure's 100 battery 625, the electronic device's 205 battery, orboth. For example, the LEDs can indicate a percentage of chargeremaining in the battery or batteries. In particular, the protectiveenclosure can include five LEDs, and when the charge level of thebattery or batteries is at forty percent, two LEDs may be illuminated.Alternately, the LEDs can indicate an estimated time remaining until oneor both batteries are depleted. In particular, if the battery orbatteries will become fully depleted in four hours, four LEDs may beilluminated. In this example, each LED represents one hour of batterylife. Other time increments can also be used and may be selectable by auser within an application running on the electronic device 205. Forinstance, when the charge of the battery or batteries is low, such asbelow about twenty percent, each LED may indicate ten or fifteen minuteincrements to provide the user with more precise information about theactual charge level of the battery or batteries. This can allow the userto better monitor and manage power consumption when no rechargingopportunities exist.

The protective enclosure 100 can be configured to fit into an optionalholster 225. The optional holster 225 can include a belt clip 226 thatcan allow the holster to attach to clothing or other objects. The beltclip 226 can rotate with respect to the holster to provide the user withgreater flexibility when positioning the holster 225. In one example,the belt clip 226 can include a ratcheting system to allow the belt clip226 to rotate with respect to the holster 225 and to lock into variouspositions selectable by the user.

FIG. 9 is a block diagram for a case 930 for an electronic device withcomponents for managing power in one embodiment of the techniquesdisclosed herein. Case 930 includes current control module 929, batterycharger 922, case battery 923, battery monitor 924, and processor 921.Back shell 215 is an example of case 930, although other configurationsare possible. The illustrated elements of case 930 may be included onone or more printed circuit boards such as circuit board 630, maincircuit board 631, and/or interface circuit board 632. Case 930 may alsoinclude mechanical components and functions as illustrated in FIGS. 1-8and the accompanying explanations.

Processor 921 may be any type of microcontroller, microprocessor,microcomputer, programmable logic device, reconfigurable circuit, orapplication specific circuit that is configured to communicate withother elements of case 930 to perform power management functions. Insome situations, these power management functions may be described as‘intelligent’ power management functions.

In some configurations, processor 921 may also communicate with anelectronic device to which case 930 is attached, communicate with apower source, communicate with other devices, or with combinationsthereof. Electronic device 205 is one example of an electronic devicewith which processor 921 communicates. Processor 921 may make use ofcomputer executable program instructions that are stored in processor921. Alternately, the computer executable program instructions may bestored in a separate memory device.

Battery 923 is a battery for supplying power to a device to which case930 is attached. Battery 923 may use one or more of a variety of batterytechnologies including lithium ion (Li-ion), lithium ion polymer (Li-ionpolymer), lead-acid, nickel cadmium (NiCd), nickel metal hydride (NiMH),nickel-zinc, alkaline, or others. Battery 923 stores chemical energywhich can be converted into electrical energy and can be provided to anelectronic device, such as electronic device 205, to which case 930 isattached. Battery 625 is one example of battery 923. In someconfigurations, battery 923 may not be contained within case 930 andcase 930 may contain an interface and/or a slot to connect to anexternal battery similar to battery 923.

Although additional batteries are possible, for purposes of simplifyingthe discussion herein, the examples provided are generally limited toexamples of cases with a single battery and electronic devices with asingle battery. However, the solutions and techniques disclosed hereinmay be implemented in a fundamentally similar manner when the caseand/or the electronic device have two or more batteries.

Battery charger 922 is a device, or collection of devices, for chargingbattery 923 using current received from current control module 929.Battery charger 922 may charge battery 923 by transitioning throughmultiple charging phases such as conditioning, constant current, andconstant voltage. The state of battery charger 922, chargingcharacteristics, or a charge mode may be commanded or controlled byprocessor 921. Processor 921 may also monitor the status of charging orcharge activities through communication with battery charger 922.Battery charger 922 may be capable of charging battery 923 usingdifferent charging algorithms (i.e., fast charge, slow charge, etc.).Battery charger 922 may also perform thermal management functions withrespect to the charging activities.

Battery monitor 924 is a device or group of devices for monitoring acondition of one or more batteries such as battery 923. Battery monitor924 may be a microcontroller peripheral that provides batterycharge/fuel gauging functions. Battery monitor 924 may use one or moreknown algorithms for fuel gauging and may provide information related tovarious parameters such as remaining battery capacity, presentrate-of-use, state-of-charge (i.e., percentage remaining), run-time toempty, battery voltage, and/or battery temperature. Battery monitor 924may be configured for or commanded to provide some or all of these typesof information to processor 921. In addition, battery monitor 924 may becapable of being configured for or commanded to these different modes byprocessor 921. In one configuration, battery monitor may be integratedwith or into battery charger 922.

Current control module 929 is a device that can be configured for orcommanded to limit or restrict the amount of current that is drawn fromor flows from a power source attached to case 930. Current controlmodule 929 may also be configured to control or limit the amount ofcurrent that flows from individual outputs of current control module929, such as to an electronic device and to battery charger 922. Currentcontrol module 929 may be pre-programmed to perform these functions ormay be configured for or commanded to perform these functions byprocessor 921. Current control module 929 may also limit surges ofcurrent when power is applied to or removed from case 930.

In one example of operation, processor 921 determines an amount ofsource current available from a power source providing power to case930. While some power sources may actually supply more power than theyare specified to provide, drawing current from a source beyond thesource's specified capabilities may damage the power source or damagethe device that is hosting the power source (i.e., a computer hosting aUSB port from which power is being drawn). Determining how much currentis available from a power source may be accomplished using one or moreof several methods including: determining a type of the power sourcebased on the type of connector used, determining a type of the powersource based on information received about the power source, determininga type of the power source based on other characteristics of the powersource, or determining the maximum capability of the power sourcethrough trial and error testing. Each of these four methods is discussedin detail below.

A first method for determining how much current is available from apower source is to use a default value based on the type of connectorthat is used to connect to the power source. For example, if the poweris supplied to case 930 through a USB connector, processor 921 may use adefault current limit of 500 mA for the current source. The power sourcemay be treated as only being able to provide this amount of current,based on the connection type, even though the power source may actuallybe capable of providing higher levels of current. For example, a chargerusing a USB connector may be capable of providing more current than isrequired by the USB standard.

A second method of determining how much current is available from apower source is to determine a type of the power source based oninformation or data received about the power source. For instance,processor 921 may receive information, through communication with thepower source or another device, indicating that the power source iscapable of supplying up to a specified maximum amount of current.Processor 921 then uses this information to direct current controlmodule 929 to limit the total current drawn from the current source. Thetotal current includes current used by battery charger 922, current usedto operate other components of case 930, and current directed to anelectronic device attached to case 930.

A third method of determining how much current is available from thepower source is to determine a type of the power source based on acharacteristic of the power source or information provided by the powersource. The power source may communicate information about its identityor characteristics to case 930 or another host device. In the case of apower source connected using a USB connector, the data lines associatedwith the connector may not be otherwise used for delivering power andmay be used to indicate capabilities of the power source. For example,APPLE IPHONE and IPOD chargers typically indicate the available currentfrom the charger by applying specific voltages on the D+ and D− USBlines. When D+ and D− are both held at 2.0V, a device may use up to 500mA of current from the power source. When D+ is held at 2.0V and D− isheld at 2.7 V, a device may use up to 1 A of current from the charger.When D− is held at 2.0 V and D+ is held at 2.7 V, a device may use up to2.1 A of current from the charger. When both D+ and D− are held at 2.7V, a device may use up to 2.3 A of current from the charger. Bydetecting voltages on these data lines, or data pins, case 930 candetermine a maximum amount of current to draw from the power source. Insome situations, the voltages or states of D+ and D− may be propagatedthrough case 930 and/or duplicated at a connector to an attachedelectronic device. This enables the electronic device to detect whattype of power source is being used even though the electronic device isnot directly connected to the power source. The power source maycommunicate it characteristics using one or more of the followingcommunication techniques: digital communication, analog communication,wireless communication, proximity detection, or optical communication.Many other configurations and methods of detecting characteristics of orinformation about the power source are possible.

A power source may use D+ and D− to indicate capabilities of the powersource, as described above, in a temporary or permanent manner. Forexample, the power source may indicate the capabilities, and/or othercharacteristics, of the power source by asserting predetermined voltageson the D+ and/or D− lines, as described above, throughout the entireperiod of time the power source is connected to a device. Alternately,the power source may assert these voltages on the D+ and D− lines foronly a shortened period of time. In one example, the power sourceasserts the capability indicating voltages for a predetermined number ofseconds when a device is initially connected and then reverts to usingthe D+ and/or the D− line for other purposes, such as transferring data.

A fourth method of determining a maximum current limit or other powercapabilities of a power source is by conducting trial and error testing.A host device using power from a power source may iteratively drawincreasing levels of power or current from the power source until thereis an indication that the power source is reaching or has reached itsmaximum capabilities. In one case, the indication that the power sourceis nearing its maximum capability may be indicated by the power sourcehaving difficulty maintaining a supply voltage. For example, if a powersource is supplying power at 5V and is having difficulty meetingincreasing current requirements, the supply voltage may begin droppingto 4.9V, 4.8V, or lower. By gradually increasing the current draw fromthe power source and detecting changes in the supply voltage, or someother characteristic of the supplied power, the host can the determine amaximum current draw for the power source.

In another situation, a maximum capability of a power source may beindicated when the power source reaches a failsafe or circuit breakermode. For example, some power sources are designed with protectioncapabilities that limit or discontinue output from the power source if amaximum power, voltage, or current draw is exceeded. A device usingpower from the source can experimentally determine this maximum power orcurrent capability by gradually increasing current or power draw fromthe power source until a failsafe of circuit breaker limit of this typeis reached and then set a maximum power or current draw value for thepower source at an amount that is less than the identified failsafe orcircuit breaker limit. In some situations, the power source may have tobe reset, rebooted, or be otherwise reconfigured after it has reached afailsafe or circuit breaker limit.

Processor 921 may also configure or command current control module 929to limit an amount of current that is delivered to each of severaloutputs of current control module 929. For example, in FIG. 9, currentcontrol module 929 has one output to battery charger 922 for chargingbattery 923 and one output which supplies power directly to anelectronic device, such as electronic device 205. Case 930 may beconfigured to manage how power or current is distributed among one ormore internal batteries and an electronic device attached to the case ina number of different ways, as will be described in detail below.

In one configuration, an electronic device connected to case 930 ispermitted to consume as much of the available current from the powersource as it can consume, up to a maximum current limit which has beendetermined by processor 921 and is being controlled by current controlmodule 929. If the electronic device is consuming less current than themaximum current limit, processor 921 then commands current controlmodule 929 to permit the balance of the available current (i.e., thecurrent limit minus the current being used by the electronic device) tobe sent to battery charger 922 for charging battery 923. The amount ofcurrent consumed by the electronic device may be monitored by currentcontrol module 929 or by a different current monitoring device withincase 930. In this way, the electronic device is permitted to use themaximum amount of current it can consume for charging its internalbattery while using any remaining available current for charging battery923 in case 930 and without exceeding the maximum current available fromthe source. In determining the balance of the available current, thecurrent consumed by other components of case 930 may also be taken intoaccount

In the configuration described above, the current drawn from the powersource is limited to the maximum value designated for that power source,but the current path from the power source to the electronic device isnot limited to any specific amount below that maximum value. Presumingthe current consumption of the electronic device does not exceed themaximum limit for the power source, the electronic device uses, in thisconfiguration, essentially the same amount of current and charges atapproximately the same rate as it would if it were connected directly tothe power source. This allows the electronic device to be charged at themaximum rate which is safe for the power source while making use of anyadditional current which is not being used by the electronic device tocharge battery 923.

In another configuration, the current supplied to the electronic devicefrom a power source is limited by case 930 to a maximum value that isless than the maximum that can be drawn from the power source. Forexample, a power source connected to case 930 may be specified forsupplying 1 A of current. However, case 930 may limit the amount ofcurrent supplied to the electronic device to a lower value. Thislimitation may be imposed in order to preserve current for charging ofbattery 923, or for other reasons such as for thermal control. This typeof control over current allocation allows case 930 to control the rateat which the electronic device is charged while reserving a designatedportion of the current to charging battery 923. In this way, battery 923and a battery in the electronic device can be charged simultaneously.The charging rate for a device or battery may be expressed as an amountof current (i.e., 400 milliamperes), an amount of power (i.e., 800milliwatts), an estimated to reach full charge (i.e., full charge in 45minutes or less), or a change in charge state per unit time (i.e., 20%increase in charge state in 15 minutes).

Also, the rate of charge of each of these two batteries and/or therelative priority of their charging can be controlled by controlling howmuch current will be allocated to each. While the current delivered tothe electronic device is primarily described as current for charging thebattery of the electronic device, it should be understood that currentdelivered to the electronic device may also be used to operate theelectronic device and/or charge the battery of the electronic devicedepending on the state of the electronic device and the state of thebattery of the electronic device.

In some situations, current control module 929 may not limit the currentthat flows from the power source directly to an electronic deviceattached to case 930, but may simply act as a current measuring devicewhich provides an indication of how much current the electronic deviceis using. Similar to previous examples, this information may be used todetermine how much additional current is available for and should beallocated to battery charger 922 for purposes of charging battery 923.

While many of the functions of case 930 are described as beingcontrolled by processor 921, it should be understood that amicroprocessor is not required to perform the techniques described here.The techniques may also be performed by a logic state machine, anapplication specific integrated circuit, and/or electrical circuitryconfigured for these purposes.

In FIG. 9, the determination regarding how the available current will beallocated among the electronic device and battery charger 922 (forcharging battery 923) may be based on a variety of static and/or dynamicfactors. These factors may include: the charge state of battery 923, thecharge state of the battery of the electronic device, the capacity ofbattery 923, the capacity of the battery of the electronic device, thetype of battery (for example, chemistry or physical arrangement), thekind of charger (wired vs. non-contact chargers), charging rates of oneor more of the batteries, ages of one or more of the batteries, numbersof charging cycles the batteries have endured, the temperature of one ormore of the batteries, another factor indicating health or condition ofone or more of the batteries, the quantity of current available from thepower source, historical usage patterns of the electronic device, userpreferences, user input, or combinations thereof. A charge state of abattery may include the current charge level as a percentage of thebattery's full capacity and may also include other informationindicative of the battery's health or capabilities. Some or all of thisinformation may be obtained from the electronic device and/or from asoftware application running on the electronic device which gathers thisinformation.

The allocation of the current may be changed when case 930 is connectedto a new power source and/or to a power source of a different capacity.The various factors listed above may also be monitored on an ongoing orperiodic basis during the charging and the allocation of current may bechanged based on changing circumstances as indicated by changes in oneor more of the factors listed above.

FIG. 10 illustrates a case 1030 interfaced to power source 1010 anddevice 1050 in one embodiment of the techniques disclosed herein. Backshell 215 is an example of case 1030. Some or all of the electricalcomponents of case 1030 may be included on one or more printed circuitboards such as circuit board 630, main circuit board 631, and/orinterface circuit board 632.

Device 1050 may be a cellular phone, smartphone, mobile communicationdevice, mobile computing device, tablet, portable computer, personalvideo player, electronic media reader, audio player, handheld scanner,camera, GPS device, or electronic computing or communication device ofanother type. In one specific example, device 1050 may be an APPLEIPHONE. Electronic device 205 is an example of device 1050. Device 1050includes device interface 1052, device battery 1053, and deviceprocessor 1051. Device processor 1051 may be any type ofmicrocontroller, microprocessor, microcomputer, analog computer,programmable logic device, reconfigurable circuit, or applicationspecific circuit that is configured to operate device 1050 or a portionof device 1050. Device battery 1053 is a rechargeable battery that isintegrated within or attached to device 1050.

Device interface 1052 provides an electrical interface between device1050 and a cable or device. Female connector 305 is an example of deviceinterface 1052. Device interface 1052 includes electrical conductors forproviding power to charge device battery 1053 as well as, in somesituations, control and data lines for communicating with deviceprocessor 1051 or other components of device 1050. In one example,device interface 1052 may comprise an APPLE 30 pin connector. In anothersituation, device interface 1052 may comprise an APPLE LIGHTNINGconnector. In yet another example, device interface 1052 may be anindustry standardized connector or a proprietary connector or interfaceassociated with another device manufacturer.

Case interface 1032 comprises an electrical and mechanical interfacethat is compatible with and mates with device interface 1052. Caseinterface 1032 enables power, and in some situations communications, tobe exchanged between case 1030 and device 1050. Male connector 810 is anexample of case interface 1032 although other interfaces and/orconnectors are possible.

In some situations, case interface 1032 may have to meet certainrequirements to be compatible with device 1050. For example, if device1050 is an APPLE IPHONE, IPAD, or IPOD, case interface 1052 may have tomeet the requirements of the APPLE Made for IPHONE/IPAD/IPOD (MFI)program. In addition, case interface 1032, or some other element of case1030, may include an authentication chip or other type of electronicauthentication device that may be necessary to establish communicationsbetween case 1030 and device 1050

Case 1030 may be designed and manufactured in variations each having acase interface 1032 that is configured to interface with differentelectronic devices or families of electronic devices. Each variation ofcase 1030 may include a different mechanical, electrical, and/orprotocol interface for interacting with the one or a family ofelectronic devices that are compatible with that particular interface.For example, one implementation of case 1030 may have an interface andprotocol capable of interfacing with a particular generation of IPHONE,while another implementation of case 1030 may have an interface capableof interfacing with a SAMSUNG mobile phone or tablet. In somesituations, case processor 1021 may execute software which is customizedfor a particular electronic device or use parameters that are customizedfor a particular electronic device. If case 1030 is interfaced to anANDROID-based phone or computing device, case interface 1032 may have tobe compliant with ANDROID Open Accessory protocol, or a similar protocolfor detecting and setting up communication between case 1030 and thephone or computing device.

Device 1050 will typically have many components in addition to thosethat are illustrated in FIG. 10, such as a display, a user interface,and/or communication components. For purposes of clarity, only thosecomponents of device 1050 that are most pertinent to the techniques andapparatuses described herein are illustrated in device 1050. However, itshould be understood that the techniques and apparatuses describedherein are not to be limited to any particular type or configuration ofelectronic device.

Power source 1010 comprises any source of power for charging case 1030and/or device 1050. Power source 1010 could be a charger compatibledevice 1050 that is plugged into a wall outlet, an automobile chargerfor device 1050, a USB port, or any other type of electrical device thatprovides current at a designated voltage or in a designated voltagerange. In some situations, power source 1010 may be integrated intoanother device, such as a USB port in a computer. Power source 1010 maybe connected to case 1030 using a cable such as cable 230.

Case 1030 includes case processor 1021, battery charger 1022, casebattery 1023, battery monitor 1024, voltage controller 1025, userinterface 1026, display driver 1027, display 1028, current limiter 1029,case power connector 1031, and case interface 1032. Case processor 1021is an example of processor 921. Battery charger 1022 is an example ofbattery charger 922. Case battery 1023 is an example of battery 923 orbattery 625. Battery monitor 1024 is an example of battery monitor 924.Current limiter 1029 is an example of current control module 929. Inaddition to the functions described below, case 1030 also providesphysical protection to device 1050. Physical protection may includeprotection from the effects of impact, shock, scratching, puncture,liquids, dust, sunlight, or other forces which could potentially damageor affect the operation of device 1050.

Case power connector 1031 is any type of electromechanical connectorthat allows power source 1010 to be electrically interconnected to case1030. Case power connector 1031 may comprise a USB connector, a mini USBconnector, a micro USB connector, a cylindrical connector, or aconnector of another type, including combinations thereof. Case powerconnector 1031 may also include conductors for communication and/ortransfer of data enabling power source 1010, or another device, tocommunicate with case processor 1021. Female connector 325 is an exampleof case power connector 1031.

In some cases, case power connector 1031 may support other functionswhen not connected to a power source. For example, case power connector1031 may also be configured to support communication between device 1050and an input device or peripheral such as: an external keyboard, amouse, a display, a GPS device, a mobile phone, a smartphone, acomputing device, or a combination thereof. In some cases, in additionsupporting the communication between one or more of these devices anddevice 1050, case 1030 may also supply power to one or more of thesedevices through case power connector 1031. In some configurations, casepower connector 1031 may also support data communications between case1030 and another computing device. In other situations, case powerconnector 1031 may comprise circuitry for receiving power from powersource 1010 inductively.

Display 1028 comprises any device for visually conveying information toa user of case 1030 and/or device 1050. Display 1028 may include one ormore of: a light emitting diode (LED), an organic light emitting diode(OLED), a liquid crystal display (LCD), electronic paper,electrophoretic ink, another type of device for visually conveyinginformation to a user, or combination thereof. Display 1028 may be madeup of a group of discrete display elements, such as a group of LEDs.Display 1028 may also be made up of a single display device, such as anLCD, containing a group of display elements or segments. LEDs 640 areone example of display 1028. Information may also be communicated to auser using a haptic device, an audio device, a shaker, and/or a speaker.

Display 1028 may be used to convey to a user information about case 1030and/or device 1050 including: a state or mode of case 1030, a state ormode of device 1050, a charge level of case battery 1023, a charge levelof device battery 1053, and/or a combined charge level of case battery1023 and device battery 1053. Display driver 1027 is a device forcontrolling, operating, driving, and/or managing the one or moreelements which make up display 1028. User interface 1026 is any type ofdevice for receiving input or a selection from a user of case 1030. Userinterface 1026 may be a switch, a button, a group of switches orbuttons, a touchscreen, a proximity sensor, a keyboard, a keypad, amouse, a trackball, a joystick, or a combination thereof.

In one example, display 1028 includes ten LEDs and display driver 1027is an LED driver that drives the ten LEDs. In this example, userinterface 1026 is a mechanically activated switch. When the switch isactivated by a user, the ten LEDs provide an indication of the chargelevel of case battery 1023 and/or device battery 1053. In oneconfiguration, the charge level may be indicated as a percentage of thetotal battery capacity, or estimated total battery capacity. Forexample, seven of the ten LEDs may be illuminated because the combinedcharge of case battery 1023 and device battery 1053 may be approximately70% of the total capacity of those two batteries. In order to conservebattery power, the LEDs may only display this information for a briefperiod of time (i.e., a few seconds) before turning off. The charge foreach of the batteries may also be displayed independently. For example,if device battery 1053 has 30% of its charge remaining and case battery1023 has 90% of its charge remaining, case 1030 may alternate betweenillumination 3 of the LEDs and 9 of the LEDs. Many other displayconfigurations and method of visually conveying information to a userare possible.

User interface 1026 may also be used for purposes other than activatingdisplay 1029. In one example, a user may hold down a switch associatedwith user interface 1026 for a predetermined number of seconds in orderto reset case processor 1021 and/or other components of case 1030. Inanother example, one or more switches that make up user interface 1026may be pressed in a predetermined pattern or sequence to change anoperating mode of case processor 1021 and/or case 1030. Inputs to userinterface 1026 may also be used to provide inputs to and/or change anoperating mode of device 1050. Display 1028 may also be used to displayinformation relating to the input of data through user interface 1026.For example, if user interface 1026 includes one or more switches whichare used to select from among various settings or menu choices, LEDswhich make up display 1028 may be used to indicate a menu item, aselection of a setting, and/or a current state of a menu item orsetting.

In another variation, the charge information may be displayed as anestimated number of hours of use remaining. This estimated number ofhours of use remaining may be determined based on information gatheredby case processor 1021 and/or battery monitor 1024 regarding usagepatterns over a period of time and power requirements associated withthose usage patterns. For example, if it is estimated that there areseven hours of use remaining based on historical or expected usagepatterns, seven of the ten LEDs may be illuminated. If there are morethan ten hours of estimated time remaining and display 1028 includesonly ten LEDs, display 1028 may convey this by successively illuminatingdiffering numbers of the LEDs. For example, 14 hours of estimated useremaining may conveyed, when the user has activated the switch, by firstilluminating ten LEDs and then subsequently illuminating only four LEDs.

The LEDs may also be operated differently when case 1030 is connected toand/or receiving power from power source 1010. For example, the LEDs maystay illuminated even though the switch has not been pressed, may fadeon and off to indicate that charging is taking place, or may cycle onand off in other patterns to convey information about a state or mode ofcase 1030 and/or device 1050.

Case 1030 may also adjust the intensity of the LEDs at preset oruser-defined times of day. For example, when connected to power source1010, case 1030 may drive the LEDs at high intensity to indicate thatcharging is taking place while driving them at a lower intensity whencharging is not taking place.

Case 1030 may also automatically reduce the intensity during the hoursof 10 PM to 6 AM, or during another window of time, in order to avoidproviding too much lighting to rooms which may often be darkened in thistimeframe. This adjustment may also be based on a user-defined window oftime in which lower intensity is preferred. In another variation, theLEDs may be dimmed based on input from a photosensor used to sense thelevel of ambient lighting in the room or based on input from a proximitysensor indicating when something (i.e., a user's face) is close todevice 1050.

In another example, display 1028 may be used to display or convey otherinformation associated with device 1050. In the example in which display1028 comprises LEDs, the LEDs are typically used to display a chargestate or charge remaining in one or more of the batteries. However,under certain circumstances, the LEDs could also be used to display analert or other information associated with device 1050. For example, ifdevice 1050 is a phone, the LEDs which make up display 1028 could beflashed brightly when there is an incoming call in order to better getthe user's attention. In another example, one or more of the LEDs couldbe dimly illuminated when the display and all other indicators on device1050 are turned off in order for a user to be able to more easily locatethe device. Any information which device 1050 might potentially displayor indicate using its own display or indicators, such as touch screen208, could potentially be replaced or supplemented through display ofinformation using display 1028 of case 1030. The information to bedisplayed can be communicated to case 1030 through communication withdevice processor 1051.

Many other types of input devices and display devices are known in theart and may be used to implement user interface 1026 and/or display1028. The apparatuses, solutions, and techniques disclosed herein arenot to be limited to any specific type of user input device, userinterface, display device, method of receiving input from a user, ormethod of displaying information to a user.

Voltage controller 1025 is a device for adjusting the voltage of poweroutput by case battery 1023 to device 1052. In one example, case battery1023 and device battery 1053 are both 3.7 volt (3.7V) batteries. In thisexample, case 1030 is designed to receive power at 5 volts (5V) becausesome common interfaces (i.e., USB) are specified to provide power at 5V.Consequently, device 1050 may also be configured to receive power at 5Vwith that voltage being internally stepped down in device 1050 (notshown) before it is applied to device battery 1053. When charging casebattery 1023, battery charger 1022, or another voltage regulation oradjustment device, steps down the 5V received from power source 1010 toan appropriate voltage for charging case battery 1023. Even though, inthis example, case battery 1023 and device battery 1053 are both 3.7Vbatteries, current provided from case battery 1023 to device battery1053 must be stepped up to 5V by voltage controller 1025 because 5V isexpected at device interface 1052 and device 1050 has been otherwisedesigned to use current supplied at 5V to charge device battery 1053.Many other combinations of voltages are possible.

In addition to adjusting the voltage output from case 1030 to device1050, voltage controller 1025 may also perform a switching function forthe power delivered from case battery 1023 to device 1050. For example,depending on a selected charge profile and the states of case battery1023 and device battery 1053, it may be desirable to prohibit currentflow from case battery 1023 to device 1050 in some circumstances. Forexample, even though device battery 1053 is not at 100% charge and case1030 is not connected to power source 1010, case 1030 may not deliverpower from case battery 1023 to device 1050 until the charge level ofdevice battery 1053 drops below a specified level (i.e., device battery1053 drops below 60% charge).

In addition to stepping voltage up and/or down, voltage controller 1025may also perform this switching function under the control of caseprocessor 1021. Alternately, the switching function may be performed bya component of case 1030 separate from voltage controller 1025.

In addition to supplying power to device 1050, case 1030 communicateswith device 1050 using case interface 1032 and device interface 1052.This communication may be used to manage and/or control various powerand battery charging related functions and/or exchange data for otherpurposes. While the communication between case 1030 and device interface1052 is illustrated as being conducted using the same interface and/orconnector that is used to supply power to device 1050, it should beunderstood that this communication may also occur using a differentinterface and/or connector than is used to supply power from case 1030to device 1050. Communication between case 1030 and device 1050 mayoccur through one or more different communication methods and/orprotocols. For example, communication between case 1030 and device 1050may occur using a wired connection, a wireless link, near fieldcommunication, magnetic communication, inductive communication, lightwave communication, infrared communication, audio frequencycommunication, motion, device attitude, or a combination thereof.

Communication between case 1030 and device 1050 may be automaticallyestablished when they are connected or may be established only whencommunication between case 1030 and device 1050 is necessary. As usedherein, the term ‘communication’ is intended to mean communicating dataor information. The term ‘communication’ is not intended to include thesupplying of power from one device to another. In some situations, case1030 may interface to case 1050 in multiple ways. For example, case 1030may transfer power to and communicate with an IPHONE using an APPLE 30pin or LIGHTNING connector. In other situations, one connector may beused to transfer power from case 1030 to device 1050 while datacommunications between them occur through another connector (forexample, through a headphone or microphone port) on device 1050.

In addition to the methods discussed above for controlling how muchcurrent an electronic device is permitted to consume, case 1030 may alsocommand or direct device 1050 to use no more than a specified amount ofcurrent by sending a command or instruction using one or more of thecommunication methods described above. In some situations, case 1030 maysend a command to device 1050, or another similar device such aselectronic device 205, directing the device to consume a specifiedamount, or no more than a specified amount, of current. This command maybe issued in the form of a specific current limit (i.e., 350 mA) or maybe a selection of one of a small number of pre-defined charging levels(i.e., charging level 2 of 4).

In one example, even though device 1050 may be capable of consuming upto 750 mA of current, case 1030 may send a command, or other type ofcommunication, to device 1050 instructing it to limit consumption to alesser amount, 400 mA for example. This type of command may be used tolimit the current consumed by device 1050 rather than by limiting itusing current limiter 1029 or current control module 929 as described inprevious examples. Existing electronic device case solutions do notprovide a means of performing these types of communications between acase and the associated electronic device. Therefore, existing solutionsdo not provide these types of intelligent charging and power managementfeatures between a case and the associated electronic device.

Case 1030 may issue a command or use other communication with device1050 to limit current to device 1050 for a number of reasons. In oneexample, case 1030 may limit the current to device 1050 in order topreserve some current for charging case battery 1023. In anotherexample, case 1030 may limit current to device 1050 in order to protectpower source 1010 from being overburdened. In another example, case 1030may limit current to device 1050 in order to synchronize the charging ofdevice battery 1053 and case battery 1023 such that they will both befinished charging at approximately the same time. This may includeongoing monitoring of the state of the two batteries and periodicadjustment of how current is allocated between the two in order todynamically compensate for their changing states and/or charging rates.In another example, case 1030 may limit current to device 1050 forthermal management purposes. Case 1030 may limit the current in order tomanage a temperature of device 1050, a temperature of a component ofdevice 1050, a temperature of case 1030, a temperature of a component ofcase 1030, a temperature of power source 1010, or a combination thereof.

Case 1030 may also allocate current between itself and device 1050 basedon how much current device 1050 is consuming. Case 1030 may use currentlimiter 1029, or a separate current measurement device within case 1030,to determine how much current device 1050 is consuming. In anotherconfiguration, device 1050 may determine how much current it isconsuming and provide this information to case 1030. If device 1050 iscurrently in an active operational mode and consuming a relatively largeamount of current, case 1030 may allocate a larger portion of thecurrent available from power source 1010 to counterbalance the effectsof device battery 1053 being depleted at a relatively high rate due tothe operation of device 1050. The allocation may be dynamically adjustedbased on how the electronic device is being used.

In some situations, case 1030 may control the allocation of currentbetween case 1030 and device 1050 in accordance with a usage profile. Ausage profile may be a default profile programmed into case 1030 or maybe a set of user-defined or user-modified parameters. For example, ausage profile may indicate that a user always wishes for device battery1053 to be fully charged before the charging of case battery 1023begins. This configuration is convenient for a user who may periodicallyuse device 1050 without case 1030 because device battery 1053 willalways have the maximum possible charge, relative to case battery 1023.If device 1050 is disconnected from case 1030 and used independent ofcase 1030 for a period of time, it may potentially be used for a longerperiod of time in this mode because the charging of device battery 1053has been maximized.

Because batteries may charge more efficiently or effectively whencharged more slowly, case 1030 may also limit the amount of currentallocated to case battery 1023 and/or device 1050 in order to accomplisha slower or more gradual charge cycle for one or more of the batteries,rather than using a larger amount of the available current to charge thebatteries serially in time (i.e., direct all or most the availablecurrent to charge one of the batteries first and then divert the currentto the second battery when the first is fully or nearly fully charged).When charged in this manner, case 1030 may be supplying less current todevice 1050 than device 1050 would consume if connected directly to apower source.

In some situations, the slow charging approach described above may alsoinvolve communication between case 1030 and device 1050 regarding whattype of charge cycle or charge mode is being used or is planned to beused. In one example, case 1030 may communicate with device 1050 toobtain information about device battery 1053 or preferred chargingcharacteristics for device battery 1053. The selection of a chargingmode may also be based on a usage profile, a user profile, environmentalconditions, a type of power source 1010, a capacity of power source,1010, or a combination thereof.

Case 1030 may also adjust the allocation of current to device 1050 basedon the operational mode of device 1050. If device 1050 is operationaland consuming current, case 1030 may allocate more current to device1050 in order to provide current for device 1050 to operate as well asto charge device battery 1053. For example, it may be desirable tocharge device battery 1053 using 500 mA of current. Case 1030 mayprovide 500 mA of current for this purpose, or may command device 1050to only draw 500 mA, when device 1050 is in a standby, low power, orhibernate mode. However, if device 1050 is active and is consuming morepower, case 1030 may change the allocation of current to device 1050 inorder to accommodate the power usage of device 1050 while maintainingthe charging of device battery 1053 at approximately the same rate as ithad been charging when device 1050 was in standby, low power, orhibernate mode. In other words, case 1030 may adjust the amount ofcurrent supplied to device 1050 in order to keep the amount of currentavailable for charging of device battery 1053 roughly constant while theoperational mode of device 1050 is changing. Case 1030 may receiveinformation about the operating mode of device 1050 throughcommunication with device 1050 using one of the methods described above,by monitoring current consumption of device 1050, or by other means.

Case 1030 may also provide improved power management functions whenattached to device 1050 with respect to the use or discharge of casebattery 1023 and/or device battery 1053. Existing solutions may fully,or nearly fully, discharge one battery before use of the other begins.However, some types of batteries operate more efficiently (i.e., canprovide more total power over time) when discharged more slowly.Consequently, using case battery 1023 and device battery 1053 tojointly, simultaneously satisfy the current needs of device 1050 mayeffectively increase the amount of power available from the twobatteries thereby increasing the time that device 1050 can be usedbefore recharging is necessary. In order to properly manage simultaneousbattery use or discharge, case 1030 may communicate with device 1050using one of the previously described methods to obtain informationregarding one or more of the following: the current charge state ofdevice battery 1053, a rate of current usage from device battery 1053 bydevice 1050, a total rate of current usage by device 1050, anoperational mode of device 1050, or a combination thereof.

In some situations, case 1030 may toggle between the various chargingand discharging operations modes described above based on a time of dayand/or a day of week. For example, a user may often make heavier use ofdevice 1050 during daytime and evening hours and infrequent use ofdevice 1050 during night hours. Therefore, case 1030 may allocateavailable current from power source 1010 to case battery 1023 and device1050 differently during these various periods. During periods of heavyuse, a user may wish the maximum amount of current to be used to chargedevice battery 1053 before charging case battery 1053 in order tomaximize the possible use time of device 1050, in the short term, ifdevice 1050 is removed from case 1030. For example, if it is midday anddevice 1050 is attached to case 1030 and case 1030 is attached to apower source in a car while the user is making a 40 minute drive, it maybe most beneficial to divert as much current as possible to chargingdevice battery 1053. Doing so may result in, for example, device batterybeing charged to a 50% level during the drive rather than device battery1053 being charged to 20% and case battery 1023 being charged to 25%during the drive if both were being charged. Because charging during thehigh use hours is more likely to be discontinued before both batteriesare fully charged, directing more of the available current to device1050 gives the user more flexibility to use the device for a longerperiod of time without being connected to case 1030 even though this maynot be the most efficient or preferred charging mode when it is expectedthat case 1030 will be connected to a charger long enough to charge bothbatteries.

In contrast, during nighttime hours, it may be more likely that powersource 1010 will remain connected for a longer period of times (i.e.,while the user is sleeping). Therefore, during these periods it may bemore efficient to simultaneously charge both batteries and/or charge oneor more of the batteries using a lower charging current (i.e., a slowercharge rate). This may result in a more complete charge while havinglittle effect on flexibility because it is more likely case 1030 willremain connected to power source 1010 for a long enough time period tofully charge both batteries.

Various charging profiles may be created for different times of days,different days of week (i.e., Saturday charge behavior is different thanweekdays). The profiles may be default profiles that are programmed intocase 1030 or device 1050, may be default profiles that have beenmodified by a user, or may be user created profiles. Case 1030 mayobtain the profiles or information about the profiles throughcommunication with device 1050. In addition, case 1030 may retrieveinformation regarding the current time or day of week throughcommunication with device 1050.

Case 1030 may make further charging or charging profile determinationsbased on other information received from device 1050. As describedabove, the usefulness of various charging profiles is dependent, atleast in part, on how long case 1030 will remain connected to powersource 1010. Therefore, case 1030 may access calendar or scheduleinformation stored on device 1050 in making charge profiledeterminations. For example, if case 1030 is plugged into a charger at12:45 PM, a default charge profile may be to attempt to fully chargedevice battery 1053 before charging case battery 1023 because it is lesslikely that the charger will remain attached for an extended period oftime during this time of day (i.e., because the user may be driving toor from lunch). However, if the retrieved calendar information indicatesthat the user is in a meeting from noon to 10:30 PM, case 1030 maycharge the batteries in slow charge and/or parallel charge mode (i.e.,charge both batteries at the same time) in order to increase batterylife and/or charge efficiency. This may be a preferred choice because,based on the calendar information, it appears that the user may bestaying in the same place for another hour and forty-five minutes andtherefore it is more likely device 1050 will remain connected to acharger for this period of time.

In one variation of the example above, case 1030 may indicate thecurrent charge mode or profile to the user, either directly usingdisplay 1028, through another element of case 1030, or through aninterface of device 1050, and give the user the option to switch toanother charging mode or profile.

In another variation of the example above, case 1030 may obtain locationinformation from device 1050 in order to make charging or charge profileselection decisions. Device 1050 may be capable of determining its ownlocation or movement using a GPS receiver, using a gyroscope, throughtriangulation, through tower identification, or other means. Case 1030may make charging or charging profile selection determinations usingthis information along with other information about the user. Case 1030may obtain some or all of this information from device 1050. Forexample, if case 1030 is connected to power source 1010 at a residentiallocation and is not moving or is connected to power source 1010 at alocation that is known to be a residence of the user, a charging profilemay be selected that is geared toward a longer charging cycle.Similarly, if the gathered information indicates that the device has avelocity above a threshold, it is likely being charged in a car andselecting a charging profile structured for periods in which the devicewill be attached for shorter periods of time may be more suitable.

In yet another variation, case 1030 may use device 1050 to accessadditional data used to make charging profile or charging leveldecisions. For example, case 1030 may identify a type of device battery1053 and make use of communication capabilities of device 1050 to accessinformation (i.e., at an Internet website) about one or more of thebatteries such as preferred charging levels, charging rates, a preferredcharging profile for a battery, information used in predicting the life,health, or discharge rate of a battery. Case 1030 may then use thisinformation in conjunction with, or in place of, the various chargeprofile criteria discussed in the examples above. In some situations, itmay be beneficial to charge device battery 1053 at a lower charging ratewhen it is near, or as it nears, full capacity. Consequently, case 1030may determine a charging rate or charging current level such that it hasan inverse relationship to the charge state, or percentage of fullcapacity, of the device battery 1053. The charging rate may beperiodically adjusted as device battery 1053 and/or case battery 1023are charged.

Case 1030 may also include capabilities to monitor its own power leveland perform mode changes accordingly. In one example, case 1030 isconnected to device 1050 but is not connected to power source 1010. Case1030 monitors the level of case battery 1023 and deactivates or shutsdown case 1030 when the level of case battery 1023 drops below apredetermined level. Case 1030 may be put into a sleep or hibernate modeor may be shut down entirely. In this way, device 1050 will no longerattempt to draw current from or communicate with case 1030 and device1050 may operate, at least temporarily, as if it is not attached to case1030 even though it may remain physically attached to case 1030.

A software application may be run on device processor 1051 of device1050, or on a processor of another device such as electronic device 205,to monitor, configure, or view data associated with the various chargingand power management features described herein. The software applicationmay reside on case 1030 and be loaded from case 1030 to device 1050 whendevice 1050 is attached to case 1030. Alternately, case 1030 may provideinstructions to device 1050 directing device 1050 to obtain the softwareapplication from another location. For example, when connected to device1050, case 1030 may provide a universal resource locator (URL) to device1050 which device 1050 can use to download to the application from awebsite or a server associated with the URL. The URL may also beassociated with a manufacturer or supplier of device 1050, amanufacturer or supplier of case 1030, an application store, or downloadsite from which the software application may be downloaded based on theURL.

In addition to the types of information described above, case 1030 mayalso provide other types of information to device 1050 or to a softwareapplication running on device 1050. For example, case 1030 may transmitone or more messages to device 1050 that include information such as: anindication that the supply of power from case 1030 to device 1050 isabout to be cut, an indication that the level of current from case 1030to device 1050 is about to be changed, information about power source1010, and/or a status of case 1030.

Case 1030 may also communicate with other devices or systems using thecommunication capabilities of device 1050. For example, case 1030 maytransmit a request to device 1050, or a software application running ondevice 1050. Then, the request is transmitted to a recipient by device1050, such as to a server over a wireless communication network. Device1050 may receive a response to the request and transmit that response tocase 1030. In one example, the request may be for a firmware update forcase 1030 and the response may include the firmware update.

In another example, historical charging and device usage information maybe collected by case 1030 and/or device 1050 and transmitted to arecipient for analysis. Based on the historical information, therecipient may provide a new recommended charging profile, pattern, oralgorithm that better suits that user's behaviors and usage patterns.Case 1030 receives, via device 1050, the new recommended chargingprofile, pattern, or algorithm and substitutes it for the previous one.In this way, case 1030 can optimize the charging algorithm for each userbased on their actual usage patterns.

The software application may communicate with case 1030 in a variety ofways. In one example, the software application, running on deviceprocessor 1051, may communicate with case 1030 using device interface1052. In another example, the software application may communicatedirectly only with device 1050 and rely on software or firmwarecontained in device 1050 to relay messages to or perform communicationswith case 1030.

In the situation where device 150 is a device designed or manufacturedby APPLE, a software application running on device 1050 may communicatewith case 1030 using the APPLE external accessory framework. Theexternal accessory framework provides a conduit for communicatingbetween APPLE devices and attached accessories. This conduit may be usedto integrate accessory level features into software applications.Features or functions of case 1030 can be integrated into a softwareapplication, if any, running on case 1030 using this framework.

Communicating with an external accessory typically requires workingclosely with the accessory manufacturer to understand the servicesprovided by that accessory. Manufacturers must build explicit supportinto their accessory hardware for communicating with iOS. As part ofthis support, an accessory must support at least one command protocol,which is a custom scheme for sending data back and forth between theaccessory and an attached app.

In one example, the software application may be configured to displayone or more of many different types of information for each batteryincluding: battery type, battery capacity, current battery charge level,battery age, battery health, and number of charge/discharge cycles. Inaddition, the software application may also determine a power remainingmetric, based on the charge remaining in each of the batteries, anddisplay an estimated amount of operation time remaining for device 1050based on the power remaining metric. The time remaining may be expressedas a percentage (i.e., 30% remaining) or as an amount of time (i.e., 2hours and 45 minutes). The estimated amount of time remaining may bebased on tracking how much power has been used over a recent period oftime, a current operating mode of device 1050, other battery lifeprediction methods, battery health, or a combination thereof. The timeremaining may be expressed as a combined figure which takes bothbatteries into account but also conveys how much of that total isprovided by each of two or more batteries.

FIG. 14 illustrates one example of a power remaining display on touchscreen 208 of an electronic device installed in protective enclosure100. In the display, outer ring 1410 shows the power remaining in thebattery in the electronic device. Inner ring 1420 shows the powerremaining in the battery in protective enclosure 100. Estimated totaltime of use remaining 1430 is indicated in the middle of the display andis based on both batteries. In addition, touch screen 208 may alsoinclude graphical indicator 1440 which illustrates power remaining.Graphical indicator 1440 may mimic information displayed on LEDs

The software application may also be configured to display informationabout the charger including: a type of the charger, how much current thecharger is capable of providing, how much current the charger iscurrently providing, how long the charger has been connected, and/or anexpected time until charging is completed.

The software application may also track and display power usage over anextended period of time. In one example, the software applicationdisplays a bar graph for a week, a month, or another period of time,that illustrates, for each day in that period, how much power wasconsumed by device 1050, how much power was added through charging, andhow much benefit was provided by case battery 1023 in case 1030. FIG. 15illustrates one example of a daily power consumption display ontouchscreen 2008 of an electronic device installed in protectiveenclosure 100. Each bar of the chart in FIG. 15 illustrates the powerusage for a day of the month. Each bar is broken into two colors. Onecolor illustrates the amount of power used by the device from its ownbattery while the other color illustrates the amount of power used bythe device from the case battery. The display may also indicate the timeof day that one or both of the batteries became depleted.

In another example, FIG. 16 illustrates alternate example of powerremaining displays on touch screen 208 of a device installed inprotective enclosure 100. The display includes a number of hoursremaining from both batteries and/or an estimate of the time of day towhich the device will be operational based on the current battery levelsand usage are displayed.

In another example, an x-y line chart displayed on touch screen 208 ofan electronic device installed in protective enclosure 100 illustratesthe change in charge of one or multiple batteries versus time of day.FIG. 17 is an example of this type of display and also includes anestimate of the number of hours of charge remaining. FIG. 18 includessimilar displays of charge remaining versus time of day for severalother days. A user of the device may use this type of multi-day displayto identify usage patterns, devise a charging strategy, and/or as inputfor defining a charging profile.

Many other formats for graphing or visually depicting charge and usageinformation are known in the art and the claimed apparatuses, solutions,and techniques are not to be limited to any particular depiction method.

In one variation, when the software application is running on device1050 and device 1050 is not connected to case 1030, the softwareapplication may also display the additional power or use time that couldpotentially be obtained if device 1050 was connected to case 1030. Insome situations, information about a manufacturer or supplier of case1030 may also be displayed in conjunction with this information.

In another variation, the software application may communicate withother instances of the software application, or a similar softwareapplication, on another device. The communication may be for purposes ofsharing charge profile information, transferring a user profile from onedevice to another, and/or sharing charge/discharge statistics.

Case 1030 may also include a solar cell or other alternate type of powersource. A solar cell can be used to supplement the power needed tooperate device 1050 and charge one or more of the batteries when case1030 is exposed to light of a sufficient intensity top generate currentfrom the solar cell. Case processor 1021, in conjunction with currentlimiter 1029, may be configured to allocate current from the solar cellamong case 1030 and device 1050. When power source 1010 is connected tocase 1030, case 1030 may perform these processes with respect to thecombined current available from power source 1010 and the solar cell.

Some smartphones and computing devices have near field communication(NFC) capabilities. NFC is defined by a set of standards for radiofrequency (RF) communication between two devices. NFC is related toradio-frequency identification (RFID) standards. Typically NFC enableddevices are able to communicate with each other after bringing them inclose proximity (i.e., a few centimeters) to each other. In somesituations, NFC communications may be used to set up or bootstrap afaster and/or more complex communication channel.

Case 1030, case 930, back shell 215, or any of the other embodimentsdescribed herein may also include an NFC repeater. For example case 1030may include an NFC repeater (not shown) because some portion of case1030 physically blocks or inhibits the lower power signal from the NFCcoil or antenna that is built into device 1050. Because theeffectiveness of NFC antenna of device 1050 may be significantlydiminished when case 1030 is attached to device 1050, case 1030 mayinclude a tune NFC repeater which repeats the signal from device 1050'sNFC transceiver in an area of case 1030 that is not blocked, or isblocked to a lesser manner, by components of case 1030.

In one example, the NFC transceiver of electronic device 205 ispositioned on the back of electronic device 205 near battery 625. Onceelectronic device 205 is attached to back shell 215, some of the powerof the NFC transceiver may be block by battery 625. A tuned NFC repeaterin back shell 215 may be located near and inductively coupled to the NFCtransceiver and routed to the other side of battery 625 in order toprovide an NFC signal that is not blocked or obscured by battery 625.

FIG. 11 illustrates a method of operating a case for an electronicdevice in one embodiment of the techniques disclosed herein. In step1110 of FIG. 11, an electrical current is received at a case for anelectronic device from a power source connected to the case. In step1120, the received electrical current is distributed between arechargeable battery in the case and the electronic device based oninformation received by the case through communication with theelectronic device.

FIG. 12 illustrates a method of operating a case for an electronicdevice in one embodiment of the techniques disclosed herein. In step1210, an amount of current available from a power source is determined.In step 1220, a current control limit is set. In some situations, thecurrent control limit is set based on the determined available current.At step 1230, a distribution of the current is determined among anelectronic device and the case for the electronic device based ondistribution factors. These distribution factors may include: a chargestate of a battery in the case, a charge state of a battery in theelectronic device, a capacity of one or both batteries, a charge rate ofone or both batteries, an age of one or both batteries, numbers ofcharging cycles the batteries have endured, a temperature of one or bothbatteries, another factor indicating health or condition of one or bothbatteries, the quantity of current available from the power source,historical usage patterns of the electronic device, user preferences,user input, or combinations thereof.

In step 1240 of the method of FIG. 12, the current is distributed basedon the determined distribution. In some situations, after current hasbeen allocated or distributed to the electronic device, all of theremaining available current from the power source is distributed to thecase and/or the case battery. In other situations, the total currentconsumed from the power source by the case, the electronic device, andany batteries being charged is less than the available current from thepower source.

In step 1250 of the method of FIG. 12, a determination is made as towhether the case has been connected to a new power source. If it isconnect to a new power source, the method returns to step 1210 and adetermination is made regarding how much current is available from thenew power source. If the case has not been connected to a new powersource, the distribution factors continue to be monitored at step 1260.The distribution of current between the case and the electronic devicemay be dynamically adjusted as conditions change.

When a case is configured to charge a case battery and provide power tothe electronic device simultaneously, a profile may indicate that boththe case battery and a battery of the electronic device are to becharged simultaneously with a preference that they are charged at ratessuch that they reach full charge at approximately the same time. At thestart of charging, the electronic battery may be 5% full and the casebattery 30% full. At the start of charging, based on the distributionfactors, 75% of the available charging current may be allocated tocharging the electronic device battery while the remaining 25% isallocated to charging the case battery. However, after time, theelectronic battery may be at 90% charge while the case battery has onlyreached 75%. In this situation, the allocation may be dynamicallyadjusted to divert more of the available current to the case battery.

FIG. 13 illustrates computer system 1300 with which some embodiments ofthe techniques disclosed herein may be utilized. Some or all of thesteps and operations associated with the techniques introduced here maybe performed by hardware components or may be embodied inmachine-executable instructions that cause a general purpose or specialpurpose computer processor programmed with the instructions to performthe steps. Alternatively, the steps may be performed by a combination ofhardware, software, and/or firmware. According to the example of FIG.13, computer system 1300 includes a bus 1390, at least one computerprocessor 1310, at least one communication interface 1330, at least onememory 1320, at least one mass storage 1340, and at least one powerinterface 1350. A removable storage media 1360 also interface to bus1390 of computer system 1300.

Computer processor 1310 can be any known computer processor,microprocessor, microcontroller, analog computing circuitry,programmable logic array, or programmable logic device. Computerprocessor 1310 may also interface to a coprocessor.

Communication interface 1330 can be any type of interface forcommunicating with another device or a network. Communication interface1330 may be configured for communicating using a wired connection, awireless connection, audio signals, light waves, infrared, or acombination thereof. Communication interface 1330 may be configured forcommunicating with or over a network such a Local Area Network (LAN),Wide Area Network (WAN), or any network to which computer system 1300connects. Communication interface 1330 may also be configured tocommunicate with an electronic device such as a cellular phone, asmartphone, a tablet, a laptop computer, a server, or a digital audiodevice. The various functions of communication interface 1330 may bedistributed across multiple communication interfaces. In one example,communication interface 1330 is a USB interface.

Memory 1320 can include random access memory (RAM), or any other type ofdynamic data storage device commonly known in the art. Memory 1320 mayalso include one or more static storage devices such as read only memory(ROM), programmable read only memory (PROM), flash memory, magneticmemory, erasable programmable read only memory (EPROM), and/orelectrically erasable programmable read only memory (EEPROM) for storingstatic data such as firmware or machine-executable instructions forcomputer processor 1310 or for another computer processor. In someconfigurations, memory 1320 may be contained within computer processor1310 or within one of the other elements of computer system 1300.

Mass storage 1340 can include one or more persistent mass data storagedevices or modules that may be used to store data, information, and/orinstructions. Mass storage 1340 may include a hard drive, a tape drive,an optical drive, flash memory, a micro electromechanical storagedevice, or a combination thereof.

Power interface 1350 can be any type of interface for receiving and/ortransmitting electrical power. The functions of power interface 1350 maybe spread across multiple power interfaces. The functions of powerinterface 1350 may also be combined into a single connector and/orinterface with communication interface 1330. For example, the functionsof communication interface 1330 and power interface 1350 may both beimplemented in the form of one or more USB interfaces.

Removable storage media 1360 can be any kind of external data storagedevice including a hard drive, a memory card, a subscriber identitymodule (SIM) card, flash memory, an optical drive, a tape drive, a microelectromechanical storage device, or a combination thereof.

Bus 1390 communicatively couples the elements of computer system 1300,as well as removable storage media 1360. Bus 1390 may conform to anindustry standard bus architecture and protocol or may use a proprietaryarchitecture and/or protocol.

FIG. 19 illustrates an example of displaying battery charge informationin one variation of the techniques disclosed herein. In FIG. 19,protective enclosure 100 is attached to electronic device 205. Asexplained in some of the examples above, electronic device 205 includesan internal battery. Protective enclosure 100 also includes a battery. Asoftware application may be run on electronic device 205 to gather anddisplay, on touch screen 208 of electronic device 205, information aboutthe charge states of the batteries. The information may be displayed inthe form of a graphical illustration or representation of theinformation. For example, the software application may display indicator1930 which indicates a charge state of the battery of protectiveenclosure 100 and display indicator 1940 which indicates a charge stateof the internal battery of electronic device 205.

In the example of FIG. 19, both batteries are fully charged. Therespective indicators indicate the fully charged state for each of thebatteries by displaying a value of “100%.” In addition, the perimetersof indicators 1930 and 1940 are shaded to indicate that the batteriesare fully charged. A user of electronic device 205 can view theinformation displayed on touch screen 208 and easily determine thecurrent charge state of each of the batteries by either viewing thedisplayed percentage or by viewing the portion of the perimeter of theindicator that is shaded. Indicator 1930 and/or indicator 1940 mayinclude an icon, text, or other information indicating which battery theindicator is associated with. For example, indicator 1940 includes anicon of a phone to convey that it is indicating the charge state of theinternal battery of electronic device 205.

Although the examples here are described primarily with respect to aninternal battery of electronic device 205 and a supplemental battery inprotective enclosure 100, the disclosed techniques are also applicableto configurations in which neither battery is internal to electronicdevice 205, as well as to configurations in which three or morebatteries are electrically connected to electronic device 205.Additional indicators that are similar to indicators 1930 and 1940 maybe included to indicate the charge state of additional batteries, ifany. In some situations, all of the indicators may be displayed on touchscreen 205 at the same time. In other situations, one or more of theindicators may be displayed on a different screen. When the indicatorsspan multiple screens, the software application may periodically switchbetween the indicator screens or a user may toggle between the displaysmanually. Many other methods of graphically indicating a charge state ofone or more batteries are possible and the techniques disclosed hereinare not intended to be limited to any particular visual or graphicaldisplay technique or mechanism.

FIG. 20 illustrates an example of displaying battery charge informationwhen one of the batteries is not fully charged. Indicator 1930 isunchanged from FIG. 19 because the battery associated with indicator1930 is still fully charged. However, indicator 1940 indicates that thebattery of electronic device 205 is now at less than a fully chargedstated. Specifically, indicator 1940 indicates that the battery ofelectronic device 205 is at 78% of charge by displaying a value of“78%,” as well as by shading only a portion of the perimeter ofindicator 1940 that is representative of 78% of the full perimeter.

In some configurations, the perimeter of the indicator may be shaded indiscrete increments that approximate, but do not necessarily exactlyequal, the displayed percentage. For example, the perimeter area may besegregated into 10 discrete sections with 8 of those 10 sections beingshaded or highlighted when the battery is at 78% charge. In anotherexample, the perimeter area may be segregated into 4 discrete segmentswith four of them being highlighted to represent, approximately, the 78%charge level.

A charge state of one or more batteries may also be indicated usingother types of visual indicators. For example, a charge state may beindicated using a non-circular indicator made up of a discrete number ofsegments where an appropriate number of the segments are illuminated,darkened, or otherwise highlight based on the charge state (e.g., 3 of 5segments are darkened when the charge state is near 60%). Indicator 1940may be configured to display in various increments such as 1%, 2%, 5%,10%, or 25% depending on the resolution of the measurement of the chargestate and/or the desired resolution for the display. In one example, thecharge state of one or more of the batteries may be measured in 1% orsmaller increments, but indicator 1930 and/or indicator 1940 may onlydisplay the charge state(s) in multiples of 5%, 10%, 25%, or some othervalue. A quantitatively indicated charge value, such as “78%,” and agraphical representation of that charge state, such as the perimeter ofindicator 1940, may be displayed with different resolutions.

FIG. 21 illustrates an example of displaying battery charge informationin a situation in which both batteries are partially discharged.Indicator 1940 indicates that the battery associated with indicator 1940has been discharged to 53% of full capacity. Indicator 1930 indicatesthat its associated battery has been discharged to 73% of full capacity.As described above, various algorithms and/or profiles may be used todetermine which of the batteries electronic device 205 should be drawingcurrent from under various circumstances. The indicators may alsoinclude icons or other information that indicates whether the associatedbattery is being charged. In this example, the battery associated withindicator 1940 is the internal battery of electronic device 205. Thisinternal battery can be charged by the battery of protective enclosure100 even when neither electronic device 205 nor protective enclosure 100is connected to an external power source. In other words, the lightningbolt icon within the phone icon indicates that the battery of protectiveenclosure 100 is currently being charged. When the battery of protectiveenclosure 100 charges the battery of mobile device 205, the valueindicated by indicator 1930 will decrease while the value indicated byindicator 1940 will. The icon indicating that a battery is being chargedmay appear within the associated indicator, as illustrated in FIG. 21,or may be displayed elsewhere on touch screen 208. The icon may alsoflash or otherwise vary in a time related manner (e.g., a lightning boltassociated with the icon that flashes on and off) to indicate that theassociated battery is being charged.

FIG. 22 illustrates an example of displaying battery charge informationwhen protective enclosure 100 is attached to an external power source.Indicator 1930 indicates that the battery of protective enclosure 100 iscurrently at 70% charge. An icon or other type of visual indicator maybe displayed in or near indicator 1930 to further indicate thatprotective enclosure 100 is plugged in or otherwise receiving power froman external power source. For example, in FIG. 22 indicator 1930includes an icon of an electrical plug to indicate that it is receivingpower from an external power source. The icon may also flash orotherwise vary in a time related manner to indicate that the battery ofprotective enclosure 100 is being charged. In some configurations, theicon may flash while one or more of the battery(s) are charging andremain solid when protective enclosure 100 is still attached to theexternal power source, but charging of the battery(s) is completed.

As described in the examples above, the current from an external powersource may be divided among two or more batteries. Various algorithmsand/or profiles may be used to determine how the current received fromthe external power source may be allocated among the two or morebatteries.

In addition to conveying charge state information as described above,the software application may also, or alternatively, convey charge stateinformation by changing a color of one or more of indicator 1930 andindicator 1940. For example, one or both indicators may be displayed inone color when the charge is above a threshold and change to a differentcolor, red for example, when the charge level of the associated batterydrops to or below that threshold. In other words, in this example,indicator 1940 turns red when the internal battery of electronic device205 is less than or equal to 20%. The indicator may then return to theoriginal color when the charge level is above that threshold, or aboveanother threshold. Color changes of the indicators, or one or more partsof the indicators, may also be used to indicate when one or more of thebatteries are being charged. For example, indicator 1930 may be greenwhen protective enclosure 100 is not connected to an external powersource and may turn blue when it is connected to an external powersource. A further distinction may be made by varying the color ofindicator when charging has completed and protective enclosure 100 isstill connected to the external power source.

FIG. 23 illustrates an example of displaying time remaining informationbased on battery charge information. Indicator 1960 displays anestimated amount of use time remaining for electronic device 205 basedon the charge state of one or more batteries. In the example of FIG. 23,the software application running on electronic device 205 has determinedthat the one or more batteries are expected to provide 7 hours and 12minutes of additional use time for electronic device 205 before beingdepleted. Based on the estimated time remaining and a current time,indicator 1950 indicates the approximate time of day at which electronicdevice 205 will shut down because the batteries are depleted. Thealgorithm(s) used to determine the values displayed by indicators 1950and 1960 may take into account one or more of many factors including,but not limited to: battery charge status, battery health, usageprofiles, usage patterns, historical behavior patterns, time of day, dayof week, location, current computing resource utilization, expectedfuture computing resource utilization, number of software applicationsor programs running, scheduled events, scheduled meetings, wirelesssignal strength, or other factors affecting how much power is being usedby electronic device 205 and protective enclosure 205 or how much poweris expected to be used by electronic device 205 in the future.

In some configurations, a user may manually toggle between the displayof FIG. 23 and one of the displays in FIGS. 19-22 or the softwareapplication may automatically switch between displays. Any combinationof indicator 1930, indicator 1940, indicator 1950, and indicator 1960may be displayed on touch screen 208. In one configuration, a user canoptionally configure which of these indicators will be displayed on aparticular screen and/or in what positions they are displayed.

In one example, a case for an electronic device includes a battery, aninterface to receive electrical current from an external power source,and a computer processor. The computer processor is configured toexecute computer-readable instructions to receive a communication fromthe electronic device, limit the received electrical current to acurrent limit, and allocate the electrical current among the battery andthe electronic device based on the received communication.

In one variation of the example above, limiting the current includesdetecting a type of the external power source and determining thecurrent limit based on the type of the external power source.

In another variation, receiving communication from the electronic deviceincludes receiving information from the electronic device indicating astate of the battery of the electronic device.

In another variation, the case charges the battery using a portion ofthe received electrical current and supplies another portion of thereceived electrical current to the electronic device. In someconfigurations, the size of the other portion is based on the state ofthe battery of the electronic device.

In another variation, the case transmits an instruction to theelectronic device directing the electronic device to draw no more than aspecified amount of current from the case.

In another variation, the case allocates current using a chargingprofile that is based on one or more of: a time of day, a day of week, acharge level of the case battery, a charge level of a battery of theelectronic device, an amount of current available from the externalpower source, and a user preference received from the electronic device.

In another example, a protective enclosure for a mobile computing deviceincludes a battery interface for interfacing to a rechargeable battery,an interface to receive electrical current from an external powersource, and electrical circuitry. The electrical circuitry is configuredto exchange communications with the mobile computing device anddistribute a portion of the received electrical current to the mobilecomputing device based on the communications.

In one variation of the example above, the electrical circuitry is alsoconfigured to determine a magnitude of the portion based on thecommunications. In some situations, the communications includeinformation indicating a charge state of the mobile computing devicebattery.

In another variation, the electrical circuitry is configured to restrictthe received electrical current from exceeding a current limit. In somecases, restricting the current may include detecting a type of externalpower source and determining the current limit based on the type ofexternal power source.

In another variation, the protective enclosure may receive user profileinformation from the mobile computing device.

In another variation, the electrical circuitry may distribute anotherportion of the received electrical current to charging circuitry in theprotective enclosure for charging the rechargeable battery. The size ofthe other portion may be determined based on a state of the rechargeablebattery.

In another example, a method of performing power management in aprotective case for an electronic device is provided. The methodincludes receiving electrical current at the protective case from apower source connected to the protective case and distributing thereceived electrical current to the protective case and to the electronicdevice based on data exchanged in a communication between the protectivecase and the electronic device.

In one variation, the method includes using a portion of the receivedelectrical current to charge a rechargeable battery interfaced to theprotective case.

In another variation, the exchanged data includes a charge state of abattery of the electronic device.

In yet another variation, the method includes sending a command from theprotective case to the electronic device instructing the electronicdevice to consume no more than a specified amount of current.

In another variation, the method includes determining a type of thepower source and limiting the received electrical current to a currentlimit based on the type of power source.

The components described above are meant to exemplify some types ofpossibilities. In no way should the aforementioned examples limit thescope of the invention, as they are only exemplary embodiments.

The foregoing disclosure has been presented for purposes of illustrationand description. Other modifications and variations may be possible inview of the above teachings. The embodiments described in the foregoingdisclosure were chosen to explain the principles of the concept and itspractical application to enable others skilled in the art to bestutilize the invention. It is intended that the claims be construed toinclude other alternative embodiments of the invention except as limitedby the prior art.

The phrases “in some embodiments,” “according to some embodiments,” “inthe embodiments shown,” “in other embodiments,” “in some examples,” “insome cases,” “in some situations,” “in one configuration,” “in anotherconfiguration” and the like generally mean that the particular feature,structure, or characteristic following the phrase is included in atleast one embodiment of the present invention and/or may be included inmore than one embodiment of the present invention. In addition, suchphrases do not necessarily refer to the same embodiments or differentembodiments.

What is claimed is:
 1. A case for an electronic device, the casecomprising: a battery; an interface to receive electrical current froman external power source; and a computer processor configured to executecomputer-readable instructions to: receive a data communication from theelectronic device; limit the received electrical current to a currentlimit; transmit an instruction to the electronic device directing theelectronic device to draw no more than a specified amount of currentfrom the case; and allocate, based on the received data communication,the received electrical current among the battery and the electronicdevice.
 2. The case of claim 1 wherein to limit the received electricalcurrent to a current limit includes to: detect a type of the externalpower source; and determine the current limit based on the type of theexternal power source.
 3. The case of claim 1 wherein to receive thedata communication from the electronic device includes to receiveinformation from the electronic device indicating a state of a batteryof the electronic device.
 4. The case of claim 3 wherein to allocate thereceived electrical current among the battery and the electronic deviceincludes to: charge the battery using a first portion of the receivedelectrical current; and supply a second portion of the receivedelectrical current to the electronic device.
 5. The case of claim 4wherein the computer processor is further configured to execute theinstructions to determine a size of the second portion based on thestate of the battery of the electronic device.
 6. The case of claim 1wherein to allocate includes to allocate using a charging profile thatis based on one or more of: a time of day, a day of week, a charge levelof the case battery, a charge level of a battery of the electronicdevice, an amount of current available from the external power source,and a user preference received from the electronic device.
 7. Aprotective enclosure for a mobile computing device, the protectiveenclosure comprising: a battery interface for interfacing to arechargeable battery; an interface to receive electrical current from anexternal power source; and electrical circuitry configured to: exchangedata communications with the mobile computing device; direct the mobilecomputing device to draw no more than a specified amount of current fromthe protective enclosure; distribute a first portion of the receivedelectrical current to the mobile computing device based on the datacommunications; and distribute a second portion of the receivedelectrical current to the battery interface based on the datacommunications.
 8. The protective enclosure of claim 7 wherein themobile computing device is one or more of: a cellular phone, asmartphone, a camera, and a tablet computer.
 9. The protective enclosureof claim 7 wherein the electrical circuitry is further configured todetermine a magnitude of the first portion based on the datacommunications.
 10. The protective enclosure of claim 7 wherein the datacommunications include information indicating a charge state of abattery of the mobile computing device.
 11. The protective enclosure ofclaim 7 wherein the electrical circuitry is further configured torestrict the received electrical current from exceeding a current limit.12. The protective enclosure of claim 11 wherein to restrict thereceived electrical current from exceeding the current limit includesto: detect a type of the external power source; and determine thecurrent limit based on the type of the external power source.
 13. Theprotective enclosure of claim 7 wherein to exchange data communicationswith the mobile computing device includes to receive user profileinformation from the mobile computing device.
 14. The protectiveenclosure of claim 7 wherein a magnitude of the second portion isdetermined based on a state of the rechargeable battery.
 15. Theprotective enclosure of claim 7 wherein to distribute the first portionincludes to determine a magnitude of the first portion using a chargingprofile that is based on one or more of: a time of day, a day of week, acharge level of the rechargeable battery, a charge level of a battery ofthe mobile computing device, an amount of current available from theexternal power source, and a user preference received from the mobilecomputing device.
 16. A method of performing power management in aprotective case for an electronic device, the method comprising:receiving electrical current at the protective case from a power sourceconnected to the protective case; transmitting a signal to theelectronic device directing the electronic device to draw no more than aspecified amount of current from the protective case; and distributing afirst portion of the received electrical current to the protective caseand a second portion of the received electrical power to the electronicdevice, wherein the first portion and the second portion are determinedbased on data exchanged in a communication between the protective caseand the electronic device.
 17. The method of claim 16 whereindistributing the received electrical current to the protective caseincludes using a portion of the received electrical current to charge arechargeable battery interfaced to the protective case.
 18. The methodof claim 16 wherein the data includes a charge state of a battery of theelectronic device.
 19. The method of claim 16 further comprising sendinga command from the protective case to the electronic device instructingthe electronic device to consume no more than a specified amount ofcurrent.
 20. The method of claim 16 further comprising: determining atype of the power source; and limiting the received electrical currentto a current limit based on the type of the power source.